Title: astronomical survay
1The real astronomy
2Whats up next ?
In this talk we will examine the different
wonders up in the sky , Look at the future
possibility in space , comets etc . Hope it
would give you bit idea of astronomy and deep sky
celestial objects . Astronomy is a subject
which not actually a subject to study but a
hobby in which you have to be an amateur.
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Galileo
310 things that can easily shock you
- 1.Quasars- Quasars are big black holes which are
formed when a star dies before being born. When
this occurs the dust particles and clouds gets
mixed with each other and it spins which forms
air to threshed and lights generated by which
starts an explosion - Which makes a quasar, these quasars then forms
into small galaxies these small either gets
bigger by adding more stars to it example Milky
Way galaxy or Andromeda galaxy (the most biggest
galaxies in the universe(till man has explored) - Â
4Magentars
- As you know, neutron stars are formed when stars
more massive than our Sun explode as supernovae.
When these stars die, they no longer have the
light pressure pushing outward to counteract the
massive gravity pulling inward. - This enormous inward force is so strong that it
overcomes the repulsive force that keeps atoms
from collapsing. Protons and electrons are forced
into the same space, becoming neutrons. The whole
thing is just made of neutrons. Did the star have
hydrogen, helium, carbon and iron before? Thats
too bad, because now its all neutrons. - You get pulsars when neutron stars first form.
When all that former star is compressed into a
teeny tiny package. The conservation of angular
motion spins the star up to tremendous
velocities, sometimes hundreds of times a second. - But when neutron stars form, about one in ten
does something really really strange, becoming
one of the most mysterious and terrifying objects
in the Universe. They become magnetars. Youve
probably heard the name, but what are they? - As I said, magnetars are neutron stars, formed
from supernovae. But something unusual happens as
they form, spinning up their magnetic field to an
intense level. In fact, astronomers arent
exactly sure what happens to make them so strong. - Â
53.Geomagnetic reversal
- A geomagnetic reversal is a change in a planet's
magnetic field such that the positions of
magnetic north and magnetic south are
interchanged. The Earth's field has alternated
between periods of normal polarity, in which the
direction of the field was the same as the
present direction, and reverse polarity, in which
the field was the opposite. These periods are
called chrons. The time spans of chrons are
randomly distributed with most being between 0.1
and 1Â million years with an average of 450,000
years. Most reversals are estimated to take
between 1,000 and 10,000 years. The latest one,
the BrunhesMatuyama reversal, occurred 780,000
years ago and may have happened very quickly,
within a human lifetime.1 A brief complete
reversal, known as the Laschamp event, occurred
only 41,000 years ago during the last glacial
period. That reversal lasted only about 440 years
with the actual change of polarity lasting around
250 years. During this change the strength of the
magnetic field weakened to 5 of its present
strength.2 Brief disruptions that do not result
in reversal are
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74.Earth losing magnetic feild
- Consequences of Earth Losing its Magnetic Field
-
- Compasses Would do Strange Things
- Image via Britannica
- Compasses are really nothing more than tiny
magnets, and like all magnets, they align
themselves with nearby magnetic fields.
 Conveniently, Earths magnetic field is strong
enough to force compasses to align north-to-south
but with our planets magnetic field gone,
compasses would point to any nearby source of
magnetism. Â Even an outcrop of magnetic rock
could do the trick.In fact, scientists have
documented this effect before. Magnetic
anomalies places on Earth where nearby natural
magnetism cause compasses to malfunction are
found around the world. In the Central African
Republic, for example, unexplained magnetic
variations in Earths crust cause compass needles
to point in random directions, rendering them
useless for navigation. If our planets magnetic
field disappeared, wandering compasses could
become the norm worldwide. - 2. Birds Couldnt Migrate for the Winter
- Humans arent the only animals that exploit
Earths magnetic field for navigation. Many
birds, sea turtles, lobsters, honeybees, salmon,
and even fruit flies have biological compasses
termed magnetoreceptors  built into their
bodies. Birds use this ability to seek warmer
climates during winter months, while sea turtles
navigate the open ocean and seek beaches to lay
their eggs. Scientists even think that most
female sea turtles return to the same beaches
every year a feat made possible in part by
their natural compasses. - If Earths magnetic field disappeared, many
animals that depend on compass navigation could
be in serious trouble. Sea turtles could
literally get lost at sea. Migratory birds might
fly in the wrong direction, threatening their
survival. Honeybees might get lost trying to
find their hives, which could impact the
pollination of flowers and other plants. With
their navigational abilities severely
compromised, these and many other organisms could
face extinction.
8Along with our biodiversity, the loss of Earths
magnetic field could alter Earths auroras, known
commonly as the Northern and Southern Lights.Â
These beautiful phenomena are created when our
planets magnetic field channels charged
particles from the sun known as the solar wind
into our planets upper atmosphere. The solar
wind is usually deflected by our magnetosphere
(the invisible shell created by Earths
magnetic field), but around the north and south
poles, the magnetosphere dips inward like a
funnel, allowing the solar wind to interact with
our upper atmosphere. The result of this
interaction are the spectacular, multicolored
bands of glowing plasma known as auroras. Auroras
on Earth have been known to shine so brightly, a
person could literally read by them. But without
Earths magnetic field, our entire upper
atmosphere would be exposed to the solar wind,
completely changing how our auroras might
appear they could even cause
95. Â Cosmic Rays Could Reach Earths Surface
- Credits tejasvi and his celestron power seeker
50 AZ telescope - Our magnetic field doesnt just give us beautiful
auroras it keeps us alive. Cosmic rays and the
solar wind are harmful to life on Earth, and
without the protection of our magnetosphere, our
planet would be constantly bombarded by a stream
of deadly particles. Â The effects of cosmic rays
on the body can be pretty terrifying. While on
lunar missions, for example, astronauts often
reported seeing flashes of light when they closed
their eyes the direct result of cosmic rays
passing through their retinas. A few even
developed cataracts years later. - Radiation and cosmic rays are a real concern for
NASA, especially when it comes to long-term
spaceflight. Astronauts on a mission to Mars
could undergo up to 1000 times the exposure to
radiation and cosmic rays that they would get on
Earth. If Earths magnetic field disappeared,
the entire human race and all of life, in fact
 would be in serious danger. Cosmic rays would
bombard our bodies and could even damage our DNA,
increasing worldwide risk of cancer and other
illnesses. The flashes of light visible when we
close our eyes would be the least of our
problems.
10Thank You